go.mod: Use explicit go-runtime-metrics-internal version

[felixge]

What does this PR do?

go.mod: Use explicit go-runtime-metrics-internal version

As suggested in
https://github.com/DataDog/go-runtime-metrics-internal/issues/10
the go-runtime-metrics-internal has been tagged with explicit versions.

This should have already fixed #3011 as future `go get -u ./...`
invocations should resolve to v0.0.3 (same as v0.0.1). See the issue
above for more details.

Fixes #3011

Motivation

Fix the issue.

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

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[pr-commenter]

Benchmarks

Benchmark execution time: 2024-12-06 09:20:31

Comparing candidate commit a7c6d95 in PR branch felix.geisendoerfer/explicit-go-runtime-metrics-version with baseline commit 9980c24 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 59 metrics, 0 unstable metrics.